centaur gas engine

[Frank Boyle]

Hi all
I have completed the cylinder head of the engine,but when setting out the valve bores my mind cleared off and I made an error of 1/16".As I have made a good job of bore and seating the valve housings I don't want to start again.My thoughts are to reduce one arm of the rockers by 1/16" but will this alter the geometry or have I got to by a new casting but at £75 I am reluctant .
Frank

[Jo]

Any chance of a photo of your booboo Frank so we can understand what you have done.

Not that I can speak mine still does not run 

Edit: Just looked at mine: if the centre is closer to the timing shaft it should not make any difference, if necessary you can adjust the curve on the bottom of the rocker arms.

Jo

[Jasonb]

Depends which direction it is out, a shorter or longer rocker arm will alter the amount the valve opens but that could be allowed for by a slight alteration to the cam lift though its not going to make a lot of difference to how the engine runs. If its sideways then a small offset could be built into the rocker arm to keep it central to the valve stem.

J

[Frank Boyle]

The bore for the valve housings is offset 1/16" towards the camshaft side and is in the correct position for the rocker arms .What size spark plug did you use Jo on your engine.I have bought a 1/4" plug but it looks a bit small.Thanks for the replys they have  eased my mind.

Frank

[Jo]

If it is the inlet the push rod will take up the offset   

I have a CM-6 on mine which looks in keeping.

Jo

[michaelr]

With only a 1/16"out, I don't think you will have a problem with your valve settings, I used alternative gears for my Centaur cam shaft drive which altered cam shaft center, the valve rocker centers and the rockers were made as drawing, the inlet push rod as Jo has said took up the difference.
The engine starts and runs with no problem, the plug is a CM-6.

Mike.

[Frank Boyle]

Thank you all for the information it has been a great help.The picture of the valves at work was good ,it's good to get an image to relate to a drawing.
Frank